This disclosure relates to a solar cell.
A solar cell in which a p-type region and an n-type region are formed in the back surface thereof, i.e., so-called a back contact solar cell has been proposed as a solar cell with high power generation efficiency (Japanese Patent Application Publication No. 2012-33666, for example). Such a back contact solar cell generally includes a region where a p-type semiconductor layer and an n-type semiconductor layer overlap each other with an insulating layer interposed therebetween.
Use of silicon nitride or the like as an insulating layer entails a problem in that nitrogen diffuses from the insulating layer into an underlying semiconductor layer in the process of manufacturing a solar cell, which gives adverse effects on the characteristics of the semiconductor layer, e.g., increase in its resistance and degradation in its passivation properties.